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Development of a single-camera volumetric thermometry for gas flows based on space division multiplexing

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Science China(Technological Sciences) 2022年第7期65卷 1646-1650页

作者： WANG Qian LIU HeCong CAI WeiWei Key Laboratory of Education Ministry for Power Machinery and Engineering School of Mechanical EngineeringShanghai Jiao Tong UniversityShanghai 200240China

Optical imaging methods have been widely applied in combustion diagnostics due to their high sensitivity, versatility, non-intrusiveness, and amenability for implementation in harsh environment [1,2]. Compared with traditional intrusive diagnostics, such as thermometry with thermocouples and manometry with pressure transducers, planar imaging methods provide richer insights into fluid dynamics and complex combustion phenomena.

关键词： planar insight flows

Mantle heterogeneity,plume-lithosphere interaction at rift controlled ocean-continent transition zone:Evidence from trace-PGE geochemistry of Vempalle flows,Cuddapah Basin,India

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Geoscience Frontiers 2018年第6期9卷 1809-1827页

作者： Th.Dhanakumar Singh C.Manikyamba K.S.V.Subramanyam Sohini Ganguly Arubam C.Khelen N.Ramakrishna Reddy CSIR-National Geophysical Research Institute(Council of Scientific and Industrial Research) Uppal RoadHyderabad 500007India Goa University Taleigao PlateauGoa 403206India Department of Geology Loyola CollegePulivendlaCuddapahAndhra PradeshIndia

This study reports major, trace, rare earth and platinum group element compositions of lava flows from the Vempalle Formation of Cuddapah Basin through an integrated petrological and geochemical approach to address mantle conditions, magma generation processes and tectonic regimes involved in their formation. Six flows have been identified on the basis of morphological features and systematic three-tier arrangement of vesicular-entablature-colonnade zones. Petrographically, the studied flows are porphyritic basalts with plagioclase and clinopyroxene representing dominant phenocrystal phases.Major and trace element characteristics reflect moderate magmatic differentiation and fractional crystallization of tholeiitic magmas. Chondrite-normalized REE patterns corroborate pronounced LREE/HREE fractionation with LREE enrichment over MREE and HREE. Primitive mantle normalized trace element abundances are marked by LILE-LREE enrichment with relative HFSE depletion collectively conforming to intraplate magmatism with contributions from sub-continental lithospheric mantle(SCLM) and extensive melt-crust interaction. PGE compositions of Vempalle lavas attest to early sulphur-saturated nature of magmas with pronounced sulphide fractionation, while PPGE enrichment over IPGE and higher Pd/Ir ratios accord to the role of a metasomatized lithospheric mantle in the genesis of the lava flows. HFSEREE-PGE systematics invoke heterogeneous mantle sources comprising depleted asthenospheric MORB type components combined with plume type melts. HFSE-REE variations account for polybaric melting at variable depths ranging from garnet to spinel lherzolite compositional domains of mantle. Intraplate tectonic setting for the Vempalle flows with P-MORB affinity is further substantiated by(i) their origin from a rising mantle plume trapping depleted asthenospheric MORB mantle during ascent,(ii) interaction between plume-derived melts and SCLM,(iii) their rift-controlled intrabasinal emplacement through Archeane Proterozoic cratonic blocks in a

关键词： Cuddapah basin Vempalle lava flows Sulphide fractionation Partial melting Plume-lithosphere Intraplate rifting

A New Interface Identification Technique Based on Absolute Density Gradient for Violent flows

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Computer Modeling in Engineering & Sciences 2018年第5期115卷 131-147页

作者： Yan Zhou Qingwei Ma School of Mathematics Computer Science and EngineeringCity University LondonNorthampton SquareLondonEC1V 0HB

An identification technique for sharp interface and penetrated isolated particles is developed for simulating two-dimensional,incompressible and immiscible two-phase flows using meshless particle methods in this paper.This technique is based on the numerically computed density gradient of fluid particles and is suitable for capturing large interface deformation and even topological changes such as merging and breaking up of phases.A number of assumed particle configurations will be examined using the technique,including these with different level of randomness of particle distribution.The tests will show that the new technique can correctly identify almost all the interface and isolated particles,and also show that it is better than other existing popular methods tested.

关键词： Meshless method Particle method two-phase flow interface identification violent flows breaking waves

Numerical simulation of multi-dimensional inviscid compressible flows by using TV-HLL scheme

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Chinese Journal of Aeronautics 2016年第6期29卷 1553-1562页

作者： Pascalin Tiam Kapen Ghislain Tchuen University of Dschang IUT-FVLISIE/L2MSPP.O.Box 134BandjounCameroon Universite des Montagnes ISSTP.O.Box 208BangangteCameroon

This paper deals with the numerical solution of inviscid compressible flows. The threedimensional Euler equations describing the mentioned problem are presented and solved numerically with the finite volume method. The evaluation of the numerical flux at the interfaces is performed by using the Toro Vazquez-Harten Lax Leer(TV-HLL) scheme. An essential feature of the proposed scheme is to associate two systems of differential equations, called the advection system and the pressure system. It can be implemented with a very simple manner in the standard finite volume Euler and Navier–Stokes codes as extremely simple task. The scheme is applied to some test problems covering a wide spectrum of Mach numbers, including hypersonic, low speed flow and three-dimensional aerodynamics applications.

关键词： Euler equations Finite volume method Hypersonic Low speed flows Three-dimensional aerodynamics applications Toro Vazquez-Harten Lax Leer(TV-HLL)

Estimation of the peak flows in the catchment area of Batna(Algeria)

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Journal of Groundwater Science and Engineering 2020年第1期8卷 79-86页

作者： SAMI Guellouh ABDELWAHHAB Filali Med ISSAM Kalla Laboratory LRNAT University of Batna-2

The limited knowledge of the variations,both spatial and temporal,of the flow patterns at the watershed level invariably leads to poor space management,generating great and often irreversible damage.Therefore,measuring peak flows appears to be not only important but even essential.Due to the absence of hydrometric stations at the outlet of the sub-basins that are part of comprehensive prevention strategy,and were established because of the high vulnerability of the city of Batna,this study provides a transformation model of rainfall into flows in the Batna watershed.This work aims to model the transformation of rainfall into flows.To estimate the Q max,two formulas were used,and Turazza's seems to be the most adequate,because it demonstrates a cumulative sub-basins flow close to the result recorded by the only hydrometric station at the outlet of Batna Watershed.From this modeling,it is possible to estimate the extreme quantiles with the return periods of 10,20,50 and 100 years for each sub-basin.Its purpose is to help design of hydraulic works and increase the resilience of development projects that might be exposed to floods.

关键词： flows Floods Empirical methods Rainfall Turazza

Predicting flows through microfluidic circuits with fluid walls

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Microsystems & Nanoengineering 2021年第6期7卷 119-127页

作者： Cyril Deroy Nicholas Stovall-Kurtz Federico Nebuloni Cristian Soitu Peter R.Cook Edmond J.Walsh Department of Engineering Science Osney Thermo-Fluids LaboratoryUniversity of OxfordOxford OX20ESUK Sir William Dunn School of Pathology University of OxfordOxford OX13REUK Cold Spring Harbor Laboratory Cold Spring HarborNYUSA

The aqueous phase in traditional microfluidics is usually confined by solid walls;flows through such systems are often predicted accurately.As solid walls limit access,open systems are being developed in which the aqueous phase is partly bounded by fluid walls(interfaces with air or immiscible liquids).Such fluid walls morph during flow due to pressure gradients,so predicting flow fields remains challenging.We recently developed a version of open microfluidics suitable for live-cell biology in which the aqueous phase is confined by an interface with an immiscible and bioinert fluorocarbon(FC40).Here,we find that common medium additives(fetal bovine serum,serum replacement)induce elastic no-slip boundaries at this interface and develop a semi-analytical model to predict flow fields.We experimentally validate the model’s accuracy for single conduits and fractal vascular trees and demonstrate how flow fields and shear stresses can be controlled to suit individual applications in cell biology.

关键词： walls flows flow

The transition from conservative to dissipative flows in class-B laser model with fold-Hopf bifurcation and coexisting attractors

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Chinese Physics B 2022年第6期31卷 39-45页

作者：李月陈增强袁明峰仓诗建 College of Artificial Intelligence Nankai UniversityTianjin 300350China Department of Earth and Space Science and Engineering York University4700 Keele StToronto M3J 1P3Canada Department of Product Design Tianjin University of Science and TechnologyTianjin 300222China

Dynamical behaviors of a class-B laser system with dissipative strength are analyzed for a model in which the polarization is adiabatically eliminated. The results show that the injected signal has an important effect on the dynamical behaviors of the system. When the injected signal is zero, the dissipative term of the class-B laser system is balanced with external interference, and the quasi-periodic flows with conservative phase volume appear. And when the injected signal is not zero, the stable state in the system is broken, and the attractors(period, quasi-period, and chaos) with contractive phase volume are generated. The numerical simulation finds that the system has not only one attractor, but also coexisting phenomena(period and period, period and quasi-period) in special cases. When the injected signal passes the critical value,the class-B laser system has a fold-Hopf bifurcation and exists torus “blow-up” phenomenon, which will be proved by theoretical analysis and numerical simulation.

关键词： conservative flows dissipative attractors coexisting phenomena fold-Hopf bifurcation class-Blaser chaotic system

On the generation of drift flows in wall-bounded flows transiting to turbulence

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Theoretical & Applied Mechanics Letters 2018年第1期8卷 48-56页

作者： Paul Manneville Hydrodynamics Laboratory CNRS-UMR 7646Ecole Polytechnique

Despite recent progress, laminar-turbulent coexistence in transitional planar wall-bounded shear flows is still not well understood. Contrasting with the processes by which chaotic flow inside turbulent patches is sustained at the local(minimal flow unit) scale, the mechanisms controlling the obliqueness of laminar-turbulent interfaces typically observed all along the coexistence range are still mysterious. An extension of Waleffe's approach [Waleffe, 1997] is used to show that,already at the local scale, drift flows breaking the problem's spanwise symmetry are generated just by slightly detuning the modes involved in the self-sustainment process. This opens perspectives for theorizing the formation of laminar-turbulent patterns.

关键词： Wall-bounded flows Plane Couette flow Minimal flow unit Self-sustainment-process Galerkin models

RESEARCH ANNOUNCEMENTS ON“STRUCTURAL STABILITY OF TRANSONIC SHOCK flows WITH EXTERNAL FORCE”

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数学杂志 2022年第3期42卷 189-192页

作者： WENG Shang-kun YANG Wen-gang School of Mathematics and Statistics Wuhan UniversityWuhan 430072China

1 Introduction and Main Results The studies of transonic shock solutions for inviscid compressible flows in different kinds of nozzles had a long history and had obtained many important new achievements during the past twenty years.Courant and Friedrichs[1]had described the transonic shock phenomenain a de Laval nozzle whose cross section decreases first and then increases.

关键词： shock compressible flows